Rock-drill.



G. R. BENNETT.

ROCK DRILL.

APPLICATION FILED NOV. 19, 1910. 1,127,396, Patented Feb. 9,1915.

IVITNESSES:

LVVENTOR.

rns NORRIS PETERS cm, WASHINGTON, 04 c.

GEORGE R. BENNETT, OF DENVER, COLORADO.

R0 GK-DRILL.

Application filed November 19, 1910.

To all whom it may concern:

Be it known that I, GEORGE R. BENNETT, a citizen. of the United States of America, residing at Denver, in the county of Denver and State of Colorado, have invented certain new and useful Improvements in Rock- Drills, of which the following is a specification.

My invention relates to improvements in rock drills and other impact machines of the type in which a reciprocatory hammer is actuated by fluid pressure to deliver a succession of impacting blows upon the end of a longitudinally movable tool.

The present invention appertains more particularly to rock drills of the character shown and described in my United States Patent No. 978,981 of December 20, 1910, and its object resides in the provision of a system of cooperative drills which are alternately actuated by the expansive actlon of one body of expansive fluid, which being used repeatedly, is replenished only, when by leakage of imperfect joints, its density has been reduced to an inadequate degree.

The accompanying drawing represents a sectional elevation of my improved system.

Referring to the drawings by numerals, each of the impact-machines comprised in the system, is composed of a cylindrical housing 2 in which a piston 4: is fitted for reciprocation to impinge upon a tool 5, longitudinally movably held in a chuck 6 at the forward end of the housing.

A rod 7, rigidly connected with the piston 4, projects through a stufling box 8 at the rear end of the housing, and it has at its outer extremity, a conoidal head 9, to provide an annular shoulder 9 which, in the operation of the machine, is engaged by the hooked extremities of two spring-Jaws 10. The latter are secured at their opposite ends to a rack 12 which is slidably mounted in suitable bearings 13, and they are provided with oppositely and inwardly projecting bosses 10 which, at the termination of the rearward movement of the rack, are engaged by an anti-friction roller 14 for the purpose of disengaging their hooked extremities from the head 9.

The two or more drill housings together with the mechanism by which their pistons are alternately retracted and released, are mounted upon a suitable support such as the plate 15 shown in the drawings.

In the construction shown, the racks 12 Specification of Letters Patent.

Patented Feb. 9, 1915.

Serial No. 593,226.

of the two impact machines extend in parallel relation to each other and are simultaneously engaged by segment gears formed at opposite ends of a circularly reciprocating element 16 which receives its movement from a rotatory crank 17 mounted on the plate 15, through the instrumentality of a pitman 18.

The air chambers of the two impact machines, which in the drawings are designated by the figures 19, are in continuous communication with a reservoir of expansible fluid, such as air under compression, which may be mounted upon a support separate from that which carries the two ma chines and which is connected with the drillhousings by flexible conduits 24.

When the hammer 4 in one of the housings is at the end of its rearward stroke, released by separation of the spring jaws 10, the fluid contained in the reservoir will by its expansive action, drive the same forcibly against the respective tool.

While the hammer of the one housing is released for its impact upon the tool, the hammer in the other housing is drawn rearwardly by action of the impelling mechanism with the result that the decrease in density of the air in the reservoir by its passage into the air chamber of the active impact machine, is compensated by the simultaneous discharge of a similar quantity of air from the chamber of the other machine and that in consequence the air in the reservoir will during the alternate actions of the two machines, remain at a substantially uniform degree of pressure.

The air contained in the reservoir is thus used repeatedly for the alternate operation of the two impact-engines and the reservoir requires replenishment only when by leakage, the density of the air has been reduced to a degree that it can no longer perform its function.

It will be understood that if so desired, more than two impact machines can be operated by connection with one and the same reservoir the compressed air in which absorbs the reactive forces and thus relieves the operating mechanism and their supports from detrimental shocks and vibration.

Having thus described my invention what I claim is:

In combination, two impact engines each comprising a housing and a reciprocating piston, a reservoir which is in continuous while one is moved in one direction by the action of the said mechanism, the other is impelled in the opposite direction by the pressure of air.

In testimony whereof I afiiX my signature 15 in presence of two witnesses.

GEORGE R. BENNETT. Witnesses:

G. J. ROLLANDET, E. M. KREMPEL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

